File: /usr/include/linux/module.h
1 /*
2 * Dynamic loading of modules into the kernel.
3 *
4 * Rewritten by Richard Henderson <rth@tamu.edu> Dec 1996
5 */
6
7 #ifndef _LINUX_MODULE_H
8 #define _LINUX_MODULE_H
9
10 #include <linux/config.h>
11 #include <linux/spinlock.h>
12 #include <linux/list.h>
13
14 #ifdef __GENKSYMS__
15 # define _set_ver(sym) sym
16 # undef MODVERSIONS
17 # define MODVERSIONS
18 #else /* ! __GENKSYMS__ */
19 # if !defined(MODVERSIONS) && defined(EXPORT_SYMTAB)
20 # define _set_ver(sym) sym
21 # include <linux/modversions.h>
22 # endif
23 #endif /* __GENKSYMS__ */
24
25 #include <asm/atomic.h>
26
27 /* Don't need to bring in all of uaccess.h just for this decl. */
28 struct exception_table_entry;
29
30 /* Used by get_kernel_syms, which is obsolete. */
31 struct kernel_sym
32 {
33 unsigned long value;
34 char name[60]; /* should have been 64-sizeof(long); oh well */
35 };
36
37 struct module_symbol
38 {
39 unsigned long value;
40 const char *name;
41 };
42
43 struct module_ref
44 {
45 struct module *dep; /* "parent" pointer */
46 struct module *ref; /* "child" pointer */
47 struct module_ref *next_ref;
48 };
49
50 /* TBD */
51 struct module_persist;
52
53 struct module
54 {
55 unsigned long size_of_struct; /* == sizeof(module) */
56 struct module *next;
57 const char *name;
58 unsigned long size;
59
60 union
61 {
62 atomic_t usecount;
63 long pad;
64 } uc; /* Needs to keep its size - so says rth */
65
66 unsigned long flags; /* AUTOCLEAN et al */
67
68 unsigned nsyms;
69 unsigned ndeps;
70
71 struct module_symbol *syms;
72 struct module_ref *deps;
73 struct module_ref *refs;
74 int (*init)(void);
75 void (*cleanup)(void);
76 const struct exception_table_entry *ex_table_start;
77 const struct exception_table_entry *ex_table_end;
78 #ifdef __alpha__
79 unsigned long gp;
80 #endif
81 /* Members past this point are extensions to the basic
82 module support and are optional. Use mod_member_present()
83 to examine them. */
84 const struct module_persist *persist_start;
85 const struct module_persist *persist_end;
86 int (*can_unload)(void);
87 int runsize; /* In modutils, not currently used */
88 const char *kallsyms_start; /* All symbols for kernel debugging */
89 const char *kallsyms_end;
90 const char *archdata_start; /* arch specific data for module */
91 const char *archdata_end;
92 const char *kernel_data; /* Reserved for kernel internal use */
93 };
94
95 struct module_info
96 {
97 unsigned long addr;
98 unsigned long size;
99 unsigned long flags;
100 long usecount;
101 };
102
103 /* Bits of module.flags. */
104
105 #define MOD_UNINITIALIZED 0
106 #define MOD_RUNNING 1
107 #define MOD_DELETED 2
108 #define MOD_AUTOCLEAN 4
109 #define MOD_VISITED 8
110 #define MOD_USED_ONCE 16
111 #define MOD_JUST_FREED 32
112 #define MOD_INITIALIZING 64
113
114 /* Values for query_module's which. */
115
116 #define QM_MODULES 1
117 #define QM_DEPS 2
118 #define QM_REFS 3
119 #define QM_SYMBOLS 4
120 #define QM_INFO 5
121
122 /* Can the module be queried? */
123 #define MOD_CAN_QUERY(mod) (((mod)->flags & (MOD_RUNNING | MOD_INITIALIZING)) && !((mod)->flags & MOD_DELETED))
124
125 /* When struct module is extended, we must test whether the new member
126 is present in the header received from insmod before we can use it.
127 This function returns true if the member is present. */
128
129 #define mod_member_present(mod,member) \
130 ((unsigned long)(&((struct module *)0L)->member + 1) \
131 <= (mod)->size_of_struct)
132
133 /* Check if an address p with number of entries n is within the body of module m */
134 #define mod_bound(p, n, m) ((unsigned long)(p) >= ((unsigned long)(m) + ((m)->size_of_struct)) && \
135 (unsigned long)((p)+(n)) <= (unsigned long)(m) + (m)->size)
136
137 /* Backwards compatibility definition. */
138
139 #define GET_USE_COUNT(module) (atomic_read(&(module)->uc.usecount))
140
141 /* Poke the use count of a module. */
142
143 #define __MOD_INC_USE_COUNT(mod) \
144 (atomic_inc(&(mod)->uc.usecount), (mod)->flags |= MOD_VISITED|MOD_USED_ONCE)
145 #define __MOD_DEC_USE_COUNT(mod) \
146 (atomic_dec(&(mod)->uc.usecount), (mod)->flags |= MOD_VISITED)
147 #define __MOD_IN_USE(mod) \
148 (mod_member_present((mod), can_unload) && (mod)->can_unload \
149 ? (mod)->can_unload() : atomic_read(&(mod)->uc.usecount))
150
151 /* Indirect stringification. */
152
153 #define __MODULE_STRING_1(x) #x
154 #define __MODULE_STRING(x) __MODULE_STRING_1(x)
155
156 /* Generic inter module communication.
157 *
158 * NOTE: This interface is intended for small amounts of data that are
159 * passed between two objects and either or both of the objects
160 * might be compiled as modules. Do not over use this interface.
161 *
162 * If more than two objects need to communicate then you probably
163 * need a specific interface instead of abusing this generic
164 * interface. If both objects are *always* built into the kernel
165 * then a global extern variable is good enough, you do not need
166 * this interface.
167 *
168 * Keith Owens <kaos@ocs.com.au> 28 Oct 2000.
169 */
170
171 #ifdef __KERNEL__
172 #define HAVE_INTER_MODULE
173 extern void inter_module_register(const char *, struct module *, const void *);
174 extern void inter_module_unregister(const char *);
175 extern const void *inter_module_get(const char *);
176 extern const void *inter_module_get_request(const char *, const char *);
177 extern void inter_module_put(const char *);
178
179 struct inter_module_entry {
180 struct list_head list;
181 const char *im_name;
182 struct module *owner;
183 const void *userdata;
184 };
185
186 extern int try_inc_mod_count(struct module *mod);
187 #endif /* __KERNEL__ */
188
189 #if defined(MODULE) && !defined(__GENKSYMS__)
190
191 /* Embedded module documentation macros. */
192
193 /* For documentation purposes only. */
194
195 #define MODULE_AUTHOR(name) \
196 const char __module_author[] __attribute__((section(".modinfo"))) = \
197 "author=" name
198
199 #define MODULE_DESCRIPTION(desc) \
200 const char __module_description[] __attribute__((section(".modinfo"))) = \
201 "description=" desc
202
203 /* Could potentially be used by kmod... */
204
205 #define MODULE_SUPPORTED_DEVICE(dev) \
206 const char __module_device[] __attribute__((section(".modinfo"))) = \
207 "device=" dev
208
209 /* Used to verify parameters given to the module. The TYPE arg should
210 be a string in the following format:
211 [min[-max]]{b,h,i,l,s}
212 The MIN and MAX specifiers delimit the length of the array. If MAX
213 is omitted, it defaults to MIN; if both are omitted, the default is 1.
214 The final character is a type specifier:
215 b byte
216 h short
217 i int
218 l long
219 s string
220 */
221
222 #define MODULE_PARM(var,type) \
223 const char __module_parm_##var[] \
224 __attribute__((section(".modinfo"))) = \
225 "parm_" __MODULE_STRING(var) "=" type
226
227 #define MODULE_PARM_DESC(var,desc) \
228 const char __module_parm_desc_##var[] \
229 __attribute__((section(".modinfo"))) = \
230 "parm_desc_" __MODULE_STRING(var) "=" desc
231
232 /*
233 * MODULE_DEVICE_TABLE exports information about devices
234 * currently supported by this module. A device type, such as PCI,
235 * is a C-like identifier passed as the first arg to this macro.
236 * The second macro arg is the variable containing the device
237 * information being made public.
238 *
239 * The following is a list of known device types (arg 1),
240 * and the C types which are to be passed as arg 2.
241 * pci - struct pci_device_id - List of PCI ids supported by this module
242 * isapnp - struct isapnp_device_id - List of ISA PnP ids supported by this module
243 * usb - struct usb_device_id - List of USB ids supported by this module
244 */
245 #define MODULE_GENERIC_TABLE(gtype,name) \
246 static const unsigned long __module_##gtype##_size \
247 __attribute__ ((unused)) = sizeof(struct gtype##_id); \
248 static const struct gtype##_id * __module_##gtype##_table \
249 __attribute__ ((unused)) = name
250 #define MODULE_DEVICE_TABLE(type,name) \
251 MODULE_GENERIC_TABLE(type##_device,name)
252
253 /* Define the module variable, and usage macros. */
254 extern struct module __this_module;
255
256 #define THIS_MODULE (&__this_module)
257 #define MOD_INC_USE_COUNT __MOD_INC_USE_COUNT(THIS_MODULE)
258 #define MOD_DEC_USE_COUNT __MOD_DEC_USE_COUNT(THIS_MODULE)
259 #define MOD_IN_USE __MOD_IN_USE(THIS_MODULE)
260
261 #include <linux/version.h>
262 static const char __module_kernel_version[] __attribute__((section(".modinfo"))) =
263 "kernel_version=" UTS_RELEASE;
264 #ifdef MODVERSIONS
265 static const char __module_using_checksums[] __attribute__((section(".modinfo"))) =
266 "using_checksums=1";
267 #endif
268
269 #else /* MODULE */
270
271 #define MODULE_AUTHOR(name)
272 #define MODULE_DESCRIPTION(desc)
273 #define MODULE_SUPPORTED_DEVICE(name)
274 #define MODULE_PARM(var,type)
275 #define MODULE_PARM_DESC(var,desc)
276 #define MODULE_GENERIC_TABLE(gtype,name)
277 #define MODULE_DEVICE_TABLE(type,name)
278
279 #ifndef __GENKSYMS__
280
281 #define THIS_MODULE NULL
282 #define MOD_INC_USE_COUNT do { } while (0)
283 #define MOD_DEC_USE_COUNT do { } while (0)
284 #define MOD_IN_USE 1
285
286 extern struct module *module_list;
287
288 #endif /* !__GENKSYMS__ */
289
290 #endif /* MODULE */
291
292 /* Export a symbol either from the kernel or a module.
293
294 In the kernel, the symbol is added to the kernel's global symbol table.
295
296 In a module, it controls which variables are exported. If no
297 variables are explicitly exported, the action is controled by the
298 insmod -[xX] flags. Otherwise, only the variables listed are exported.
299 This obviates the need for the old register_symtab() function. */
300
301 #if defined(__GENKSYMS__)
302
303 /* We want the EXPORT_SYMBOL tag left intact for recognition. */
304
305 #elif !defined(AUTOCONF_INCLUDED)
306
307 #define __EXPORT_SYMBOL(sym,str) error config_must_be_included_before_module
308 #define EXPORT_SYMBOL(var) error config_must_be_included_before_module
309 #define EXPORT_SYMBOL_NOVERS(var) error config_must_be_included_before_module
310
311 #elif !defined(CONFIG_MODULES)
312
313 #define __EXPORT_SYMBOL(sym,str)
314 #define EXPORT_SYMBOL(var)
315 #define EXPORT_SYMBOL_NOVERS(var)
316
317 #else
318
319 #define __EXPORT_SYMBOL(sym, str) \
320 const char __kstrtab_##sym[] \
321 __attribute__((section(".kstrtab"))) = str; \
322 const struct module_symbol __ksymtab_##sym \
323 __attribute__((section("__ksymtab"))) = \
324 { (unsigned long)&sym, __kstrtab_##sym }
325
326 #if defined(MODVERSIONS) || !defined(CONFIG_MODVERSIONS)
327 #define EXPORT_SYMBOL(var) __EXPORT_SYMBOL(var, __MODULE_STRING(var))
328 #else
329 #define EXPORT_SYMBOL(var) __EXPORT_SYMBOL(var, __MODULE_STRING(__VERSIONED_SYMBOL(var)))
330 #endif
331
332 #define EXPORT_SYMBOL_NOVERS(var) __EXPORT_SYMBOL(var, __MODULE_STRING(var))
333
334 #endif /* __GENKSYMS__ */
335
336 #ifdef MODULE
337 /* Force a module to export no symbols. */
338 #define EXPORT_NO_SYMBOLS __asm__(".section __ksymtab\n.previous")
339 #else
340 #define EXPORT_NO_SYMBOLS
341 #endif /* MODULE */
342
343 #ifdef CONFIG_MODULES
344 #define SET_MODULE_OWNER(some_struct) do { (some_struct)->owner = THIS_MODULE; } while (0)
345 #else
346 #define SET_MODULE_OWNER(some_struct) do { } while (0)
347 #endif
348
349 #endif /* _LINUX_MODULE_H */
350